As techniques for automatically detecting and canceling abnormalities of electric devices, the following techniques are known.
Patent Literature 1 discloses a latch-up automatic canceling device for a programmable controller. When a latched-up occurs in the programmable controller, the latch-up automatic canceling device automatically cancels the latch-up.
Patent Literature 2 discloses an I/O relay terminal that controls one load by operating a plurality of relays with one input signal from a sequencer. This I/O relay terminal has a fault detecting function. Specifically, when one of the relays has a fault, the details of the fault are displayed on a display unit, and the relay having the fault is forcibly turned off.
Patent Literature 3 discloses a technique for preventing an inrush current or an overcurrent in one load unit in an electrical device including a plurality of load units. Specifically, a breaker with an overcurrent tripping function and an overcurrent preventing circuit are provided in each of the load units.